Dual-chamber mixing device for syringes

Abstract

A mixing device and a retractable syringe comprising the mixing device are provided. The mixing device includes a concentric outer barrel forming an outer cavity and an inner barrel having an inner cavity. A mixing plunger is slidably located within the outer cavity. A seal located in the outer cavity is axially movable into the aperture or the outer barrel from a first position in sealing engagement with the one or more apertures in the inner cavity in response to depressing the mixing plunger The second position between the vent holes. This causes depressing the mixing plunger to force a first substance from the outer chamber through the aperture to mix with a second substance in the inner chamber. The mixed substance in the lumen is then delivered through the syringe, which then retracts the needle.

Description

Technical field [0001] The invention relates to a mixing device for a syringe. More particularly, the present invention relates to a retractable syringe mixing device capable of storing, mixing, and injecting one or more medicinal substances. Background technique [0002] It is known to provide a syringe including a mixing device for mixing the deliverable substance before injection. This allows the diluent to be added to the dehydrated, lyophilized, dried or powdered active substance, for example, immediately before injection, which is particularly useful for substances that undergo deterioration or lose activity when stored in the form of hydrates. [0003] Most mixing devices for syringes utilize a continuous cavity, where the syringe has a barrel with a first proximal cavity and a second distal cavity separated by, for example, a membrane or elastomer seal. Many such continuous cavity mixing syringes utilize bypass protrusions at the cross-section of the barrel to enable flui...

AI Technical Summary

Problems solved by technology

This venting requirement can create difficulties and require additional equipment and processing steps, such as requiring the lumen to be filled under vacuum to remove all air from the lumen and the distal portion of the outer barrel beneath the second reconstitution seal

[0007] Typically, prior art mixing devices comprising concentric cylinders are structurally complex and often require rotating the cylinders to align the one or more small holes that allow the liquid substance to flow from one chamber to the other middle

In addition to this, the various arrangements of sterility, sealing and venting that have been used present severe limitations in terms of ease of manufacture and handling of mixing devices

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